Topic Contents

Knee Problems and Injuries

Topic Overview

Most people have had a minor knee problem at one
time or another. Most of the time our body movements do not cause problems, but
it's not surprising that symptoms develop from everyday wear and tear, overuse,
or injury. Knee problems and injuries most often occur during sports or
recreational activities, work-related tasks, or home projects.

The
knee is the largest joint in the body. The upper and lower bones of the knee
are separated by two discs (menisci). The upper leg bone (femur)
and the lower leg bones (tibia and fibula) are connected by
ligaments,
tendons, and muscles. The surface of the bones inside
the knee joint is covered by
articular cartilage, which absorbs shock and provides
a smooth, gliding surface for joint movement. See a picture of the
structures of the knee.

Although a knee problem is often caused by an
injury to one or more of these structures, it may have another cause. Some
people are more likely to develop knee problems than others. Many jobs, sports
and recreation activities, getting older, or having a disease such as
osteoporosis or arthritis increase your chances of
having problems with your knees.

Sudden (acute) injuries

Injuries are the most common
cause of knee problems. Sudden (acute) injuries may be caused by a direct blow
to the knee or from abnormal twisting, bending the knee, or falling on the
knee. Pain, bruising, or swelling may be severe and develop within minutes of
the injury. Nerves or blood vessels may be pinched or damaged during the
injury. The knee or lower leg may feel numb, weak, or cold; tingle; or look
pale or blue. Acute injuries include:

Sprains,
strains, or other injuries to the ligaments and
tendons that connect and support the kneecap.

Breaks (fracture) of the
kneecap, lower portion of the femur, or upper part of the tibia or fibula. Knee
fractures are most commonly caused by abnormal force, such as a falling on the
knee, a severe twisting motion, severe force that bends the knee, or when the
knee forcefully hits an object.

Kneecap
dislocation. This type of dislocation occurs more
frequently in 13- to 18-year-old girls.

Pieces of bone or tissue (loose bodies) from a fracture or dislocation that may get caught in the joint and
interfere with movement.

Knee joint
dislocation. This is a rare injury that requires great
force. It is a serious injury and requires immediate medical care.

Overuse injuries

Overuse injuries occur with
repetitive activities or repeated or prolonged pressure on the knee. Activities
such as stair climbing, bicycle riding, jogging, or jumping stress joints and
other tissues and can lead to irritation and inflammation. Overuse injuries
include:

Inflammation of the small sacs of fluid that
cushion and lubricate the knee (bursitis).

Inflammation of the tendons
(tendinitis) or small tears in the tendons
(tendinosis).

Irritation and inflammation of the band of
fibrous tissue that runs down the outside of the thigh (iliotibial band syndrome).

Conditions that may cause knee problems

Problems not
directly related to an injury or overuse may occur in or around the
knee.

Osteoarthritis
(degenerative joint disease) may cause knee pain that is worse in the morning
and improves during the day. It often develops at the site of a previous
injury. Other types of arthritis, such as
rheumatoid arthritis,
gout, and
lupus, also can cause knee pain, swelling, and
stiffness.

Osgood-Schlatter disease causes pain,
swelling, and tenderness in the front of the knee below the kneecap. It is
especially common in boys ages 11 to 15.

A problem elsewhere in the body, such as a
pinched nerve or a problem in the hip, can sometimes cause knee
pain.

Osteochondritis dissecans causes pain and decreased
movement when a piece of bone or cartilage or both inside the knee joint loses
blood supply and dies.

Treatment

Treatment for a knee problem or injury may
include first aid measures, rest, bracing, physical therapy, medicine, and, in
some cases, surgery. Treatment depends on the location, type, and severity of
the injury as well as your age, health condition, and activity level (such as
work, sports, or hobbies).

Severe pain (8 to 10): The pain
is so bad that you can't stand it for more than a few hours, can't sleep, and
can't do anything else except focus on the pain.

Moderate pain (5 to 7): The pain is bad enough to disrupt your
normal activities and your sleep, but you can tolerate it for hours or days.
Moderate can also mean pain that comes and goes even if it's severe when it's
there.

Mild pain (1 to 4): You notice the pain,
but it is not bad enough to disrupt your sleep or activities.

Major trauma is any event that can
cause very serious injury, such as:

A fall from more than
10 ft (3.1 m) [more than
5 ft (1.5 m) for children under
2 years and adults over 65].

A car crash in which any vehicle
involved was going more than
20 miles (32 km) per
hour.

Any event that causes severe bleeding that you cannot
control.

Any event forceful enough to badly break a large bone (like an arm bone or leg bone).

When an area turns blue, very pale, or cold, it can mean that there has been a sudden change in the blood
supply to the area. This can be serious.

There are other reasons
for color and temperature changes. Bruises often look blue. A limb may turn
blue or pale if you leave it in one position for too long, but its normal color
returns after you move it. What you are looking for is a change in how the area
looks (it turns blue or pale) and feels (it becomes cold to the touch), and
this change does not go away.

Pain in children under 3 years

It can be hard to tell how much pain a baby or toddler is in.

Severe pain (8 to 10): The
pain is so bad that the baby cannot sleep, cannot get comfortable, and cries
constantly no matter what you do. The baby may kick, make fists, or
grimace.

Moderate pain (5 to 7): The baby is
very fussy, clings to you a lot, and may have trouble sleeping but responds
when you try to comfort him or her.

Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds
when you try to comfort him or her.

Pain in children 3 years and older

Severe pain (8 to 10): The pain
is so bad that the child can't stand it for more than a few hours, can't sleep,
and can't do anything else except focus on the pain. No one can tolerate severe
pain for more than a few hours.

Moderate pain (5 to 7): The pain is bad enough to disrupt the child's normal activities and
sleep, but the child can tolerate it for hours or days.

Mild pain (1 to 4): The child notices and may complain of the pain,
but it is not bad enough to disrupt his or her sleep or activities.

Symptoms of infection may
include:

Increased pain, swelling, warmth, or redness in or
around the area.

Red streaks leading from the area.

Pus draining from the area.

A fever.

Certain health conditions and medicines weaken the immune system's ability to fight off infection and
illness. Some examples in adults are:

Diseases such as diabetes, cancer, heart disease,
and HIV/AIDS.

Long-term alcohol and drug
problems.

Steroid medicines, which may be used to treat a variety
of conditions.

Chemotherapy and radiation therapy for
cancer.

Other medicines used to treat autoimmune
disease.

Medicines taken after organ transplant.

Not
having a spleen.

With severe bleeding, any of these may
be true:

Blood is pumping from the wound.

The
bleeding does not stop or slow down with pressure.

Blood is quickly soaking through bandage after bandage.

With moderate bleeding, any of these may
be true:

The bleeding slows or stops with pressure but
starts again if you remove the pressure.

The blood may soak through
a few bandages, but it is not fast or out of control.

With mild bleeding, any of these may be
true:

The bleeding stops on its own or with
pressure.

The bleeding stops or slows to an ooze or trickle after
15 minutes of pressure. It may ooze or trickle for up to 45 minutes.

Shock is a life-threatening condition that may quickly occur
after a sudden illness or injury.

Symptoms of shock (most of which will be present) include:

Passing out (losing consciousness).

Feeling very dizzy or
lightheaded, like you may pass out.

Feeling very weak or having
trouble standing.

Not feeling alert or able to think clearly. You
may be confused, restless, fearful, or unable to respond to questions.

Shock is a life-threatening condition that may occur quickly
after a sudden illness or injury.

Symptoms of shock in a child may include:

Passing out (losing consciousness).

Being very sleepy or hard
to wake up.

Not responding when being touched or talked to.

Breathing much faster than usual.

Acting confused.
The child may not know where he or she is.

Seek Care Now

Based on your answers, you may need care right away. The problem is likely to get worse without medical care.

Call your doctor now to discuss the symptoms and
arrange for care.

If you cannot reach your doctor or you don't have
one, seek care in the next hour.

You do not need to call an
ambulance unless:

You cannot travel safely either by driving
yourself or by having someone else drive you.

You are in an area
where heavy traffic or other problems may slow you down.

Make an Appointment

Based on your answers, the problem may not improve without medical
care.

Make an appointment to see your doctor in the
next 1 to 2 weeks.

If appropriate, try home treatment while you
are waiting for the appointment.

If symptoms get worse or you have
any concerns, call your doctor. You may need care sooner.

Call 911 Now

Call 911 Now

Put direct, steady pressure on the
wound until help arrives. Keep the area raised if you can.

Postoperative Problems

Home Treatment

Home treatment may help relieve
pain, swelling, and stiffness.

Rest and protect an
injured or sore area. Stop, change, or take a break from any activity that may
be causing your pain or soreness. When resting, place a small pillow under your
knee.

Ice will reduce pain and swelling.
Apply
ice or cold packs immediately to prevent or minimize swelling. Apply the ice
or cold pack for 10 to 20 minutes, 3 or more times a day.

For the first 48 hours after an injury, avoid
things that might increase swelling, such as hot showers, hot tubs, hot packs,
or alcoholic beverages.

After 48 to 72 hours, if swelling is gone,
apply
heat and begin
gentle exercise with the aid of moist heat to help
restore and maintain flexibility. Some experts recommend alternating between
heat and cold treatments.

Compression, or wrapping the
injured or sore area with an elastic bandage (such as an Ace wrap), will help
decrease swelling.

Don't wrap it too tightly, since this can
cause more swelling below the affected area. Loosen the bandage if it gets too
tight. Signs that the bandage is too tight include numbness, tingling,
increased pain, coolness, or swelling in the area below the
bandage.

Don't expect the bandage to protect or stabilize a knee
injury.

Talk to your doctor if you think you need to use a wrap for
longer than 48 to 72 hours. A more serious problem may be present.

Elevate the injured or sore
area on pillows while applying ice and anytime you are sitting or lying down.
Try to keep the area at or above the level of your heart to help minimize
swelling.

Reduce stress on your sore knee (until you can get advice
from your doctor):

Use a cane or crutch in the hand opposite
your painful knee.

Use two crutches, keeping weight off the leg
with the sore knee. You can get canes or crutches from most pharmacies.
Crutches are recommended if a cane causes you to walk with a limp.

Gently massage or rub the area to relieve pain and
encourage blood flow. Do not massage the injured area if it causes
pain.

Aspirin (also a nonsteroidal
anti-inflammatory drug), such as Bayer or Bufferin

Talk to your child's doctor before switching back and
forth between doses of acetaminophen and ibuprofen. When you switch between two
medicines, there is a chance your child will get too much medicine.

Safety tips

Be sure to follow these
safety tips when you use a nonprescription medicine:

Carefully read and follow all directions
on the medicine bottle and box.

Symptoms to watch for during home treatment

Your knee becomes hard to move or swelling lasts for more than 2 days.

Your
knee, lower leg, or foot becomes pale or cool or looks
blue.

Symptoms do not improve with home
treatment.

Symptoms become more severe or frequent.

Prevention

The following tips may prevent knee
problems.

General prevention tips

Wear your seat belt in a motor
vehicle.

Don't carry objects that are too heavy. Use a step stool.
Do not stand on chairs or other unsteady objects.

Wear knee guards
during sports or recreational activities, such as roller-skating or soccer.

Stretch before and after physical exercise, sports, or
recreational activities to warm up your muscles.

Use the correct
techniques or positions during activities so that you do not strain your
muscles.

Use equipment appropriate to your size, strength, and
ability. Avoid repeated movements that can cause injury. In daily routines or
hobbies, look at activities in which you make repeated knee
movements.

Consider taking lessons to learn the proper technique
for sports. Have a trainer or person who is familiar with sports equipment
check your equipment to see if it is well suited for your level of ability,
body size, and body strength.

If you feel that certain activities
at your workplace are causing pain or soreness from overuse, call your human
resources department for information on other ways of doing your job or to talk
about using different equipment.

Tips specific to the knee

Keep your knees and the muscles that support
them strong and flexible. Warm up before activities. Try the following
stretches:

When playing
contact sports, wear the right shoes that are made for the surface you are
playing or running on, such as a track or tennis court.

Replace
running shoes every 300 to 500 miles (480 to 800 kilometers).
Experts recommend getting new athletic shoes every 3 months or after 500 miles
of wear.

Tips specific to female athletes

Sports trainers
recommend training programs that help women learn to run, jump, and pivot with
knees bent to avoid knee injuries. In sports such as soccer, basketball, and
volleyball, women who bend their knees and play low to the ground have fewer
knee injuries than women who run and pivot with stiff legs.

Knee brace use

Some people use knee braces to prevent
knee injuries or after a knee injury. There are many types of knee braces, from
soft fabric sleeves to rigid, metal hinged braces, that support and protect the
knee. If your doctor has recommended the use of a knee brace, follow his or her
instructions. If you are using a knee brace to help prevent problems, follow
the manufacturer's instructions for use.

Keep bones strong

Eat healthy foods such as milk, cheese, yogurt, and dark green, leafy vegetables like broccoli. For more
information, see the topic
Healthy Eating.

Exercise and stay active. Talk to your doctor about exercises and activities that are right for you. Begin slowly, especially if you have been inactive. For more information, see
the topic
Fitness.

Don't drink more than 2 alcoholic drinks a day if you are a man, or 1 alcoholic drink a day if you are a woman. Drinking alcohol increases your chances of having weak bones (osteoporosis). It also increases your chances of falling.

Do not smoke or use other tobacco products. Smoking increases your chances of having osteoporosis. It also causes problems with the blood supply in your legs and slows healing. For more information, see the topic
Quitting Smoking.

Possible abuse

Knee injuries such as bruises, burns, fractures, cuts, or punctures may be caused by abuse. Suspect possible abuse when an injury cannot be explained or does not match the explanation, repeated injuries occur, or the explanations for the cause of the injury change. You may be able to prevent further abuse by reporting it and seeking help.

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